Question

A bullet with a mass of 4.1 g and a speed of 650 m/s is fired at a block of wood with a mass of 9.6x10-2 kg. The block rests on a frictionless surface and is thin enough that the bullet passes completely through it. Immediately after the bullet exits the block, the speed of the block is 21 m/s. a. What is the speed of the bullet when it exits the block? b. Is the final kinetic energy of this system equal to, less than, or greater than the initial kinetic energy?

Answer 1

the it, v is the initial speed of bullet & m is the mass of the bullet ten, initial linear momentum it, u, is the velocity of the Combined bullet-block systen , then by conservation of linear momentum piamua (mama, Now, if u is the enit speed of the bullet dul be the speed of the block, tun, tinad morentur - Pf=mu'tmo"= Pismo - mormolamu 2) -mu'tmuz ma'

given, v=650 mis ma 4.14103ky m= 9.6*1072 kg & v' = 21mis hence, -/9.6*102 ( 4.10021 - 158.2926829 mis l'a 158.29 mis / cappoon) since there is some energy loss due to collision Cenergy has been lost against friction ), hence, the final kinetic energy of the system is less than the initial Kinetic energy.